Generally, in case of wireless telecommunication network of a mobile telecommunication system, due to the local restriction, there is existed a small amplitude blocked shadow zone or an impossible shielded space for transmitting and receiving of mobile telecommunication terminal. The shadow zone can be included all area having a topographic structure which intensity of propagation is extremely low by nature and artificial obstacle such as a mountain, a basement of the building, an inside of building, and so on.
The radio frequency repeater is commonly used as apparatus to be possible for receiving and transmitting of a mobile telephone and a radio paging from frequency shadow region with using a method of re-radiating amplified signal through antenna after eliminating noise to select a weak signal that relays in the existing signal in shield space and shadow region in which frequency arrival is difficult, such as mountains, tunnels, underground parking area or buildings. This radio frequency repeater operates a function to relay with re-amplified signal of the base station so as to have a good quality of service in whenever and from anywhere with covering frequency shadow region and shielded space in existing service area of a base station.
Said radio frequency repeater is connected a donor antenna means for receiving and transmitting wireless signal with a base station and a coverage antenna means for receiving and transmitting wireless signal with a mobile telecommunication terminal. The donor antenna receives a downlink signal of the mobile telecommunication terminal from the base station and amplifies the download signal in the radio frequency repeater and then transmits amplified download signal to the mobile telecommunication terminal through the coverage antenna, and the coverage antenna receives uplink signal of the base station from the mobile telecommunication terminal and amplifies the uplink signal, and then transmits the uplink signal to the base station through the donor antenna.
However, FIG. 1 illustrates a drawing of linkage for antenna of outdoor type radio frequency repeater in the prior art that shows a donor antenna (10) and a coverage antenna (20) is separated from a radio frequency repeater (30), and operates with using by a patch antenna or a yagi antenna of outdoor type for ensuring an isolation between the donor antenna (10) and the coverage antenna (20), the radio frequency repeater (30) of the prior art need to set up the donor antenna (10) and the coverage antenna (20) when the radio frequency repeater (30) is set up in a telegraph pole or a separate frame.
Moreover, FIG. 2 illustrates a drawing for antenna installation of indoor small amplitude output radio frequency repeater and indoor radio frequency repeater with built-in a patch antenna of the prior art. As showing said FIG. 2, it is a coverage antenna with built-in a patch antenna and shows to use with connecting a donor antenna (10) for ensuring isolation between receiving and transmitting antenna of radio frequency repeater (30) by RF (Radio Frequency) cable (40), to use one-body type radio frequency repeater with an omni antenna instead of a patch antenna, but the donor antenna (10) must use as separating or shielding with radio frequency repeater (30) for ensuring isolation.